The present invention relates to testing and test apparatus and more specifically a test apparatus for railway wheels. These wheels are generally utilized on all types of railway vehicles including passenger cars, locomotives and freight cars. The majority of the wheels are utilized on freight cars and application of a quick and reliable analytical apparatus for these wheels is desired to expedite their evaluation prior to shipment for use. The reasons for the quick and reliable evaluation is not just the desire to increase productivity for shipment, but even more to evaluate wheel quality for expediting reworking, to minimize inventory, and to provide rapid evaluation of the manufacturing process for corrective measures.
Railway wheels must meet the specifications promulgated by the Association of American Railroads (AAR), which generally serves as the rail industry standard setter. The railway wheels must have the correct physical characteristics for use for their intended purpose. The AAR has defined specifications for wheel chemical composition, wheel hardness based on a Brinnell hardness test and finally the wheel must meet the specifications for various physical dimensions and parameters, such as rotundity, eccentricity and dimensional tolerance.
As in most gears, shafts and other rotating components, railway wheel specifications normally required that the wheel is round at its periphery; its axle bore is aligned with the wheel central longitudinal axis; it is flat on its front and rear faces; and, it must have a proper tread diameter, as well as proper thickness and proper tread face taper. All of these physical characteristic standards, and others, must be met to provide a railway wheel that is acceptable to the purchaser and meets the above-noted AAR specifications. The testing of these wheels with conventional jigs, fixtures and gages is time consuming and awkward, as each wheel typically weighs in excess of 600 pounds. As a consequence, handling of the wheels is difficult and the degree of accuracy may in some measure be dependent upon the skill of the inspector or the quality of an inspection tool for measuring a particular dimension or characteristic. However, there is no presently known apparatus that will measure a plurality of dimensions and characteristics of a railway wheel, with or without contact of the wheel, and provide all the necessary parametric tests of the wheel for evaluation against the standards of the AAR.